Magnetic door latch



Sept. 25, 1962 F. c. BENSON MAGNETIC DOOR LATCH Filed Aug. 15,. 1960 n m 0 I 0 5 4 MW Q10 1 w "1 0 \l .l 1, HHHI m a n 2 .T m P! 3 I Z. MM MMW HW MIM 7 h I INVENT OR Fr/ *2 C. Benson United States Patent ()1 3,055,690 MAGNETIC D0011 LATCH Fritz C. Benson, West Haven, Conn, assignor to The H. B. Ives Company, New Haven, Conn., a corporation of Connecticut Filed Aug. 15, 196i), Ser. No. 49,501 4 Claims. (Cl. 292251.5)

This invention relates to magnetic catches for use on cupboard doors and the like, and relates more particularly to a magnetic catch which includes a stationary striker plate mounted on the cupboard door, for example, and a magnet unit mounted on the door frame, or perhaps the under side of a cupboard shelf, in such a way that it may be adjusted on the cabinet to maintain contact with the magnetically attractable striker plate when the door is closed. The magnet unit is of the type which includes a bar magnet sandwiched between pole pieces engageable with the striker plate, the magnet and the pole pieces being mounted in a holder forming a part of the magnet unit. The magnetic catch is also of the type in which the pole pieces are mounted by the holder for self-adjustment with respect to the striker plate so that the pole pieces may engage the striker plate over substantial surface areas and maintain a firm magnetic hold therewith despite minor dislocations of the striker plate or the magnet unit occasioned by warping of the cabinet, wear of the parts, etc. The magnetic catch is also of the type wherein greater adjustments between the striker plate and the pole pieces may be effected by limited sliding movement of the magnet unit as a whole on its support.

One object of the invention is to provide an improved magnetic catch of the type characterized above. A further object of the invention is to provide a magnetic catch having improved means for mounting and supporting a magnet element on a support such as a cabinet door frame.

In the accompanying drawings:

FIG. 1 is a fragmentary elevational view of a magnetic catch embodying the invention and showing the catch mounted on a cupboard or the like;

FIG. 2 is a view similar to FIG. 1 but illustrates the magnet unit with certain portions broken away;

FIG. 3 is an enlarged sectional view taken on line 3-3 of FIG. 1; and

FIG. 4 is a sectional view taken on line 4-4 of FIG. 2.

In the drawing, the magnet unit is indicated generally at and is shown rigidly secured to a cupboard door frame 11. The striker plate, which is formed of magnetic material and which cooperates with the magnet unit 10, is indicated at 12 and is shown rigidly secured to the cupboard door 13 as by a screw 14 extending through the plate. The striker plate is flat and presents a substantial surface area to the magnet unit 10 with which it cooperates.

The unit ltl includes a magnet holder 15 formed of nonmagnetic material such as sheet aluminum. The holder 15 is constituted by a case which has a single open side, opening toward the striker plate 12, and which in the present instance is constituted by two separate parts. One of the last-named parts is a four-sided element 16 and the other is a bottom element 17. In the illustrated form the holder is elongated and holds two magnet elements, indicated generally at 18, one above another. However, it should be understood that the number of magnet elements held by the holder is a matter of choice, as under some conditions the use of a single magnet element is sufficient.

Each magnet element 18 comprises twin pole pieces 19 of plate-like construction which sandwich a permanent magnet 20 therebetween. The magnet 20', which is of ice the bar type, may be formed of any one of a number of well-known and widely used materials employed for the purpose of constructing permanent magnets. For example, the magnet may be constructed by employing powdered metal which is pressed into a suitable block which is subsequently magnetized.

The twin pole pieces 19 of each magnet element which are formed of magnetic material so as to be magnetized by the magnet of the element 18, project beyond the magnet and project through the side opening of the holder 15 for engagement with the striker plate of the catch. As will appear more fully hereinafter, the pole pieces 19 of each magnet element 18 are mounted in the holder for movement independently of one another, the magnet of each element also being mounted for movement independently of the pole pieces. The pole pieces of each magnet element 18 are mounted for three different types of limited movement, that is, firstly, they may slide toward and away from the striker plate; secondly, they may move angularly on a horizontal axis; and thirdly, they may move angularly on a vertical axis. To this end each magnet element 18 is mounted in the holder by a pin 21, i.e., one pin 21 being provided for the upper element 18 and one pin 21 being provided for the lower element 18; and in the form illustrated in the drawing by way of example, each pin 21 is fixed in the holder 15 and the corresponding magnet element is adapted to move on the pin.

The pole pieces 19 of each magnet element are centrally apertured, as at 22, and the magnet 20 of the element is centrally apertured, as at 23. The apertures 22 and 23 loosely receive the corresponding pin 21 which extends through the holder 15. Each pin 21 may be constituted by a rivet which, in the illustrated form, is inserted in the holder through the top thereof and which is provided with a head 24 to abut the top in a manner best shown in FIG. 3. The rivet 21 is shouldered, as at 25, to abut the bottom of the holder interiorly thereof. Each rivet 21 extends through an external depression or channel 26 which permits the rivet to be headed, as at 27, in substantially flush relation to the bottom of the holder or case 15.

It is important in this riveted construction that each magnet element has clearance with the case, and to insure proper clearance of the magnet elements, spacers, indicated generally at 28, are provided to extend between the top and bottom of the case interiorly thereof. These spacers tend to prevent the top and bottom of the case from being crushed against the corresponding sides of the magnet elements 18. The shoulders 25 of the rivets, which engage the bottom of the case interiorly thereof, of course, tend to prevent crushing of the case during the assembly of the magnet unit. However, the spacers 28 serve a dual purpose, that is, they also serve to receive the mounting fasteners or screws 29 which secure the magnet unit 10 in place on the door frame or the like, and, as will appear more fully hereinafter, these spacers are movable in the case to permit the magnet unit to be adjusted bodily on the door frame.

To receive the screws 29 which mount the magnet unit, the top of the elongated case at its respective ends is provided with transversely extending slots 36 which register with similar and somewhat wider slots 31 formed in the bottom 17 of the case at the respective ends thereof. The screws 29 extend through the corresponding slots 30 and 31 and extend through the corresponding spacers 23 which are of tubular construction, having body portions 32 extending between the top and bottom of the case and neck portions 33 extending into the respective slots 31 to retain the spacers in these slots and thereby maintain the spacers in alignment with the respective slots 30. The body portion 32 of each spacer presents an annular shoulder, as at 34, in opposing relation to the bottom of the case, that is, interiorly thereof. The shoulder 34 coacts with the bottom of the case to tend to prevent the case from being crushed by the screws 29 during the installation of the magnet unit. However, the spacers 28 are slidable in the slots 31 so that when fasteners, such as the screws 29, are assembled in the spacers, the fasteners, with the spacers, may be adjusted relatively to the case in a direction transversely of the latter. This permits the magnet unit to be bodily adjusted toward and away from the striker plate by merely sliding the magnet unit on its cupboard support, without removal of the screw fasteners. It will be understood, of course, that to adjust the magnet unit on the cupboard, it is necessary to first loosen the screws 29 which extend through the case and mount the unit on the cupboard. The magnet unit may thereafter be moved on the screws to adjust the pole pieces 19 of the magnet elements toward and away from the striker plate with which they cooperate. The pole pieces, when properly adjusted, should have their leading edges in flatwise engagement with the striker plate when the cupboard door is closed. When the magnet unit is in the desired position, the screws 29 are tightened so that their heads bear against the top of the case and hold the magnet unit tightly against the cupboard in a manner to inhibit dislocation of the unit.

In the illustrated form of the magnetic catch only two mounting screws 29 are employed to mount the magnet unit on its support, and only two spacers 28 are provided. The spacers are held captive by the slots 31 in the region of the central vertical plane of the magnet unit. In the illustrated form which employs two magnet elements 18, these elements are arranged in upwardly spaced relation to one another in the case so as not to interfere with each other. Resilient means 35 is interposed between the case and each of the magnet elements 18 urging the pole pieces of the element outwardly in the case toward the striker plate. This resilient means also tends to limit angular movement of the pole pieces on their horizontal axes, and also tends to return the pole pieces to their square positions shown in FIG. 1 in which the projecting edges of the pole pieces are substantially parallel to the longitudinal axis of the case 15. In the illustrated form the resilient means 35 acting on the pole pieces is constructed from a length of resilient rubber-like material which extends the length of the case and is sandwiched between the rear wall of the case and the magnet elements 18 in the manner shown in FIG. 2. The resilient strip 35 also tends to reduce rattling of the magnet elements in the case during the opening and closing of the cupboard door.

In accordance with the foregoing disclosure there is provided a magnetic catch of improved construction. One advantage of the catch resides in the provision of improved means for mounting and supporting a magnet element on a support such as a cabinet door frame. Another advantage resides in the provision of movable spacers in the case of the magnet unit which receive the mounting screws of the unit. As previously indicated these spacers tend to prevent crushing of the case by the mounting fasteners. Still another feature of the magnetic catch resides in the provision of a case for the magnet elements, which does not require mounting flanges or cars to be attached to a support such as a cupboard door frame.

While only one form of the magnetic catch has been illustrated in the drawing and described above, it will be apparent to those versed in the art that the catch may take other forms and is susceptible of various changes in details without departing from the principles of the invention and the scope of the appended claims.

What I claim is:

1. In a magnetic catch having a striker plate, a magnet unit for cooperation with the striker plate, comprising a case of box-like shape having a chamber opening toward the striker plate, a magnet element disposed in the chamber and supported from the case, said element including a permanent magnet and having magnetized pole pieces extending from the case for engagement with the striker plate, the case at opposite sides of the magnet element having means defining twin slots registering with one another and opening into the chamber from the top and bottom of the case, the slots being normal to the plane of the striker plate for receipt of case-mounting fasteners, and spacers in the case extending between the top and bottom walls thereof to prevent the walls of the case from being crushed by the fasteners, the spacers being of sleeve-like form and registering with the corresponding slots for receipt of the fasteners, the spacers being movable lengthwise in the respective slots to permit adjustment of the case on the fasteners toward and away from the striker plate, the spacers being two in number and eing held captive in certain of said slots.

2. In a magnetic catch having a striker plate, a magnet unit for cooperation with the striker plate, comprising a case of box-like shape having a chamber opening toward the striker plate, a magnet element disposed in the chamber and supported from the case, said element including a permanent magnet and having magnetized pole pieces extending from the case for engagement with the striker plate, the case at opposite sides of the magnet element having means defining twin slots registering with one another and opening into the chamber from the top and bottom of the case, the slots being normal to the plane of the striker plate for receipt of case-mounting fasteners, and spacers in the case extending between the top and bottom walls thereof to prevent the walls of the case from being crushed by the fasteners, the spacers being of sleeve-like form and registering with the corresponding slots for receipt of the fasteners, the spacers being movable lengthwise in the respective slots to permit adjustment of the case on the fasteners toward and away from the striker plate, the spacers being two in number and having reduced extensions extending into certain of said slots to maintain said spacers captive in the last-mentioned slots.

3. In a magnetic catch having a striker plate, a magnet unit for cooperation with the striker plate, comprising a case of box-like shape forming a chamber opening toward the striker plate, a magnet element disposed in the chamber and supported from the case, said element including a permanent magnet and having magnetized pole pieces extending from the case for engagement with the striker plate, the case at opposite sides of the magnet element having means defining twin slots registering with one another and opening into the chamber from the top and bottomof the case, the slots being normal to the plane of the striker plate for receipt of case-mounting fasteners, and sleeve-like spacers in the case extending between the top and bottom walls thereof to prevent the walls of the case from being crushed by the fasteners and registering with the corresponding slots for receipt of the corresponding fasteners, the spacers being movable lengthwise in the respective slots to permit adjustment of the case on the fasteners toward and away from the striker plate, and the spacers having means thereon co-acting with means on the case to maintain said spacers in registry with the slots.

4. In a magnetic catch having a striker plate, a magnet unit for cooperation with the striker plate, comprising a case of box-like shape forming a chamber opening toward the striker plate, a magnet element disposed in the chamber and supported from the case, said element including a permanent magnet and having a part thereof extending from the case for engagement with the striker plate, the case at opposite sides of the magnet element having means defining twin slots registering with one another and opening into the chamber from the top and bottom of the case, the slots being normal to the plane of the striker plate for receipt of case-mounting fasteners, and sleeve-like spacers in the case extending between the 5 6 top and bottom walls thereof to prevent the walls of the References Cited in the file of this patent case from being crushed by the fasteners and registering UNITED STATES PATENTS w1th the corresponding slots for receipt of the corresponding fasteners, the spacers being movable length- 211941408 Sluss 1940 wise in the respective slots to permit adjustment of the 5 2,240,035 Catherau 1941 case on the fasteners toward and away from the striker 2,508,305 Teetor May 1950 plate, and the spacers being two in number and having 2,812,203 Scholten 5, 1957 means thereon co-acting with means on the case to main- 2,837,366 Loeb June 1958 tain said spacers in registry with the slots. 

